Google has kept a promise it made last year: Site speed is now a ranking factor in Google's algorithm, and is already in place for U.S. searchers. But Google also cautions web site owners not to sacrifice relevance in the name of faster web pages, and even says this new ranking factor will impact very few queries. More on that below, but first the background on today's announcement from Google Fellow Amit Singhal and Matt Cutts, head of Google's web spam team.